You can try like below
In Your View Page
<% using (Html.BeginForm())
{%>
<input type="checkbox" name="week" value="Sunday" />Sunday
<input type="checkbox" name="week" value="Monday" />Monday
<input type="checkbox" name="week" value="Teusday" />Teusday
<input type="checkbox" name="week" value="Wednesday" />Wednesday
<input type="checkbox" name="week" value="Thursday" />Thursday
<input type="checkbox" name="week" value="Friday" />Friday
<input type="checkbox" name="week" value="Saturday" />Saturday
<input type="submit" value="post" />
<%}%>
And
in your controller
public ActionResult Index(FormCollection cs, string[] week)
{
string[] selectedcheckoxes = week;
// your code goes here
return View();
}